wish
Simple windowing shell
Synopsis
wish
?-encoding name? ?fileName arg arg
...?
add an example, a script, a trick and tips
examples
description
Wish is
a simple program consisting of the Tcl command language, the
Tk toolkit, and a main program that reads commands from
standard input or from a file. It creates a main window and
then processes Tcl commands. If wish is invoked with
arguments, then the first few arguments,
?-encoding name? ?fileName?
specify the name of a script file, and, optionally, the
encoding of the text data stored in that script file. A
value for fileName is recognized if the appropriate
argument does not start with “-”.
If there are no
arguments, or the arguments do not specify a
fileName, then wish reads Tcl commands interactively
from standard input. It will continue processing commands
until all windows have been deleted or until end-of-file is
reached on standard input. If there exists a file
“.wishrc” in the home directory of the
user, wish evaluates the file as a Tcl script just
before reading the first command from standard input.
If arguments to
wish do specify a fileName, then
fileName is treated as the name of a script file.
Wish will evaluate the script in fileName
(which presumably creates a user interface), then it will
respond to events until all windows have been deleted.
Commands will not be read from standard input. There is no
automatic evaluation of “.wishrc” when
the name of a script file is presented on the wish
command line, but the script file can always source
it if desired.
Note that on
Windows, the wishversion.exe program
varies from the tclshversion.exe
program in an additional important way: it does not connect
to a standard Windows console and is instead a windowed
program. Because of this, it additionally provides access to
its own console command.
options
-encoding
name
Specifies the encoding of the
text stored in │ fileName. This
option is only recognized prior to │ the
fileName argument.
-colormap new
Specifies that the window should have a new private
colormap instead of using the default colormap for the
screen.
-display display
Display (and screen) on which to display window.
-geometry geometry
Initial geometry to use for window. If this option is
specified, its value is stored in the geometry global
variable of the application’s Tcl interpreter.
-name name
Use name as the title to be displayed in the
window, and as the name of the interpreter for send
commands.
-sync
Execute all X server commands synchronously, so that
errors are reported immediately. This will result in much
slower execution, but it is useful for debugging.
-use id
Specifies that the main window for the application is to
be embedded in the window whose identifier is id,
instead of being created as an independent toplevel window.
Id must be specified in the same way as the value for
the -use option for toplevel widgets (i.e. it
has a form like that returned by the winfo id
command).
Note that on some platforms
this will only work correctly if id refers to a Tk
frame or toplevel that has its
-container option enabled.
-visual
visual
Specifies the visual to use for
the window. Visual may have any of the forms
supported by the Tk_GetVisual procedure.
--
Pass all remaining arguments through to the
script’s argv variable without interpreting
them. This provides a mechanism for passing arguments such
as -name to a script instead of having
wish interpret them.
_________________________________________________________________
application name and class
The name of the application, which is used for purposes such as
send commands, is taken from the -name option, if
it is specified; otherwise it is taken from fileName, if
it is specified, or from the command name by which wish
was invoked. In the last two cases, if the name contains a “/”
character, then only the characters after the last slash are used
as the application name.
The class of the application, which is used for purposes such as
specifying options with a RESOURCE_MANAGER property or
.Xdefaults file, is the same as its name except that the first
letter is capitalized.
keywords
shell, toolkit
option processing
Wish automatically processes all of the command-line
options described in the OPTIONS summary above. Any other
command-line arguments besides these are passed through to the
application using the argc and argv variables
described later.
prompts
When wish is invoked interactively it normally prompts for
each command with “% ”. You can change the prompt by
setting the variables tcl_prompt1 and tcl_prompt2.
If variable tcl_prompt1 exists then it must consist of a
Tcl script to output a prompt; instead of outputting a prompt
wish will evaluate the script in tcl_prompt1. The
variable tcl_prompt2 is used in a similar way when a
newline is typed but the current command is not yet complete; if
tcl_prompt2 is not set then no prompt is output for
incomplete commands.
script files
If you create a Tcl script in a file whose first line is
#!/usr/local/bin/wish
then you can invoke the script file directly from your shell if
you mark it as executable. This assumes that wish has been
installed in the default location in /usr/local/bin; if it is
installed somewhere else then you will have to modify the above
line to match. Many UNIX systems do not allow the #! line
to exceed about 30 characters in length, so be sure that the
wish executable can be accessed with a short file name.
An even better approach is to start your script files with the
following three lines:
#!/bin/sh
# the next line restarts using wish \
exec wish "$0" "$@"
This approach has three advantages over the approach in the
previous paragraph. First, the location of the wish binary
does not have to be hard-wired into the script: it can be
anywhere in your shell search path. Second, it gets around the
30-character file name limit in the previous approach. Third,
this approach will work even if wish is itself a shell
script (this is done on some systems in order to handle multiple
architectures or operating systems: the wish script
selects one of several binaries to run). The three lines cause
both sh and wish to process the script, but the
exec is only executed by sh. sh processes
the script first; it treats the second line as a comment and
executes the third line. The exec statement cause the
shell to stop processing and instead to start up wish to
reprocess the entire script. When wish starts up, it
treats all three lines as comments, since the backslash at the
end of the second line causes the third line to be treated as
part of the comment on the second line.
The end of a script file may be marked either by the physical end
of the medium, or by the character, “\032” (“\u001a”, control-Z).
If this character is present in the file, the wish
application will read text up to but not including the character.
An application that requires this character in the file may
encode it as “\032”, “\x1a”, or “\u001a”; or may generate it by
use of commands such as format or binary.
variables
Wish sets the following Tcl variables:
argc
Contains a count of the number of arg arguments (0 if
none), not including the options described above.
argv
Contains a Tcl list whose elements are the arg arguments
that follow a -- option or do not match any of the options
described in OPTIONS above, in order, or an empty string
if there are no such arguments.
argv0
Contains fileName if it was specified. Otherwise, contains
the name by which wish was invoked.
geometry
If the -geometry option is specified, wish copies
its value into this variable. If the variable still exists after
fileName has been evaluated, wish uses the value of
the variable in a wm geometry command to set the main
window’s geometry.
tcl_interactive
Contains 1 if wish is reading commands interactively
(fileName was not specified and standard input is a
terminal-like device), 0 otherwise.